Conveyorized motor grader blade with retractable end bits

ABSTRACT

A blade assembly for a motor grader having a power driven endless belt conveyor for forcibly moving material to one side of the blade assembly is provided with end bits for facilitating operations such as bank cutting, ditching and the like in which stress may be concentrated at one end of the blade assembly. The end bits greatly reduce the wear and risk of damage which can otherwise occur at the cutting end of the conveyor. While the movement of the conveyor tends to prevent jamming of materials between the conveyor and end bit at the cutting end of the assembly, an opposite situation prevails at the discharge end. To avoid jamming at the discharge end, the end bits are retractable whereby only the bit at the cutting end need be maintained in the operative position.

United States Patent mi Stedman et al.

[45] Dec. 11, 1973 [54] CONVEYORIZ'ED MOTOR GRADER BLAD WITH RETRACTABLEEND BITS [73] Assignee: Caterpillar Tractor Co., Peoria, Ill.

954,386 4/1910 Ganser 172/782 X Primary Examiner-Robert E. PulfreyAssistant Examiner-Stephen C. Pellegrino Attorney-Donald J. McRae et al.

[57] ABSTRACT A blade assembly for a motor grader having a power drivenendless belt conveyor for forcibly movin'g material to one side of theblade assembly is provided with end bits for facilitating operationssuch as bank cutting, ditching and the like in which stress may beconcentrated at one end of the blade assembly. The end bits greatlyreduce the wear and risk of damage which can otherwise occur at thecutting end of the conveyor. While the movement of the conveyor tends toprevent jamming of materials between the conveyor and end bit at thecutting end of the assembly, an opposite situation prevails at thedischarge end. To avoid jamming at the discharge end, the end bits areretractable whereby only the bit at the cutting end need be maintainedin the operative position.

5 Claims, 5 Drawing Figures CONVEYORIZED MOTOR GRADER BLADE WITHRETRACTABLE END BITS BACKGROUND OF THE INVENTION This invention relatesto motor graders and more particularly to the cutting blade component ofmotor graders which intercepts earth or the like and carries suchmaterial to one side of the path of travel of the grader.

The blade of a conventional motor grader is normally angled relative tothe direction of travel of vehicle in order to cause intercepted earthto travel to one side of the blade. One undesirable effect of thisangling of the conventional blade is that the width of cut is therebyreduced. ln certain specialized types of motor grader operations such asbank cutting, ditching and the like wherein material` should preferablybe carried upward as well as sidewardly, reliance on angling of theblade may not be fully satisfactory.

In orderto overcome these problems, side casting motor grader bladeshave been developed in which the conventional rigid blade is replacedwith a blade assembly defned in part by an endless belt conveyor drivenby a motor whereby material is forcibly carried to one side of the cut.In many instances, such a conveyorized blade need not be angled and thusa cut having a width equal to the full length of the blade may be madethereby increasing the working efficiency of the grader. In instanceswhere the blade must be sloped such as in ditching, bank cutting and thelike, the conveyor action is much more efficient with respect tocarrying material towards the elevated end of the bladefA conveyorized'side casting motor grader of this general type is disclosed inco-pending application Ser. No. 15,664 now abandoned, of Marvin E.Beyers, et al., filed Mar. 2, 1970, and entitled MOTOR GRADER WITH POWERACTUATED SIDE CASTING MEANS. A notable problem with conveyorized motorgrader blades is that an endless belt conveyor tends to be lessresistant to wear and damage then the conventional rigid mold board orblade and is more expensive to replace. The resultant relatively highmaintenance and repair costs have tended to discourage wide spread useof this otherwise highly advantageous construction.

In many motor grader operations, one end of the blade assembly does alarge proportion of the earth cutting and the cut material then travelsalong the blade and is discharged around the opposite end. In theseoperations, the cutting end of the blade sustains the greatest stressconcentrations and risk of damage. This occurs, for example, in levelgrading where one end of the blade cuts along a window and in ditchingand bank cutting operations where the lower end of the sloped blade isrelatively more exposed to wear and damage.

To reduce wear and damage it has sometimes been the practice to provideend bits which are short rigid blade like cutting members extendingoutward from the ends of the conveyor to relieve the end of the conveyoritself of much of the task of cutting into virgin soil. When wear ordamage does occur, it is much simpler and more economical to replacesuch end bits than to replace the conveyor itself. However, theconventional end bit itself is subject to problems as a narrow passageis necessarily present between the end bit and the adjacent end of themoving conveyor and rocks or other debris can become jammed between theconveyor and end bit. This does not tend to occur at the cutting endsince the movement of the conveyor at this end is such as to tend todraw such objects away from the passage between the conveyor andadjacent end bit. However, an opposite situation. prevails at thedischarge end where the conveyor movement tends to pull small rocks andthe like into the gap between the conveyor and end bit. As aconsequence, damage, jamming and severe wear tend to occur at thedischarge end of a conveyorized motor grader blade equipped with endbits.

` SUMMARY OF THE INVENTION This invention provides an end bit on aconveyorized motor grader blade assembly which is selectivelyretractable. The end bit may be positioned to form an extension of theearth intercepting surface to relieve the adjacent end of the conveyorof much of the earth cutting work and may also be shifted to minimizethe risk of jamming when the adjacent conveyor end functions as thedischarge end of the assembly. In one form of the invention means areprovided for manually shifting the position of the end bit and inanother form, powered means provide for shifting one end bit into theoperative position and for simultaneously shifting another end bit atthe opposite end of the conveyor to the inactive protected position.

Accordingly it is an object of this invention to increase the operatingefficiency of motor graders having conveyorized blade assemblies and toreduce wear, maintenance cost, and the risk of damage in connection withsuch mechanisms.

The invention together with further objects and advantages thereof willbest be understood by reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a perspective view of a motor grader having poweredretractable end bits in accordance with the invention,

FIG. 2 is a plan section view of the conveyorized blade assembly of themotor grader of FIG. l taken along line II-II thereof,

FIG. 3 is a foreshorted elevation view of the back of the conveyorizedblade assembly of FIG. 2 taken along line III-Ill, thereof,

FIG. 4 is a plan view of a second embodiment of a conveyorized motorgrader blade assembly having retractable end bits in accordance with theinvention, and

FIG. 5 is a front elevation view of the blade assembly of FIG. 4.

Referring now to FIG. 1 there is shown a motor grader l1 which may be ofconventional construction except for the side casting blade assembly l2to be hereinafter described. Salient features of such a motor grader mayinclude an engine 13 and an operators station 14 supported on rearwheels 16 and a mainframe member 17 which extends forward to a bolster18 supported on front wheels 21. A triangular drawbar 22 has a forwardend coupled to bolster 18 by a ball and socket joint 23 and supports arotatable blade circle 24 to which blade assembly 12 may be attached byangled arms 26 at each side of the blade circle. Lift mechanisms 27 andblade circle rotating means 28 are provided whereby the operator mayraise, lower, slope and angle the blade circle, suitable detailedconstruction for such blade circle positioning means being well known inthe art.

Blade assembly 12 has a frame 31 attached to the blade circle throughthe angled arms 26 and which normally extends in a substantiallytransverse direction beneath the central portion of the vehicle althoughit may, as described above, be selectively angled or be sloped at oneside or the otherof the vehicle by appropriate operation of theconventional blade circlel positioning means. Referring now to FIGS. 1to 3 in conjunction, a cylindrical drive drum 32 is supported at one endof frame 31 for rotation about a vertical axis through the end thereofand an idler drum 33 is similarly supported at the opposite end of theframe for rov tation about a parallel axis. The endless belt conveyor34, preferably having grousers 36, is engaged on drums 32 and 33 wherebyrotation of the drive drum 32 causes the portion of the belt forming theforward facing earth intercepting surface 38 to travel continuously fromone end of the balde assembly l2 to the opposite end thereby forciblycarrying earth to one side of the motor grader. In order to drive thebelt 34, a reversible fluid operated rotary motor 39 is mounted on frame31 and coupled to a pulley 41 of the drive drum 32 by means such as adrive belt 42. Motor 39 is reversible so that material can beselectively discharged at either 'side of the motor grader.

To provide additional support for the forward or earth interceptingsurface 38 of belt 34 a series of vertical rollers 43 may extend betweenthe upper and lower portions of frame 3l behind surface 38. To reducewear of the lower edge of belt 34, a small fixed cutting edge 44 issecured along the forward edge of the under side of frame 31 and extendsa short distance forward and downward from the belt.

As described to this point, the blade assembly 12 is effective toperform the usual function of a motor grader blade in that as thevehicle is driven forward with the blade assembly 12 in a workingposition, surface 38 of belt 34 intercepts earth and forcibly carriessuch earth to one side of the path of travel. However, as previouslypointed out, rapid wear of the conveyor belt would occur in the absenceof further structure. Such wear and possible damage tends to beconcentrated at the end of the belt which is cutting into a maximumdepth of undisturbed soil which end is normally the end at which belt 34moves forwardly around the adjacent drum. Thus in the grading operationdepicted in FIG. 1, the end of the blade assembly 12 which is on theoperators right is cutting into a bank of earth 46 and belt 34 istraveled in the direction indicated by arrow 47. In this mode ofoperation, the right end is most subject to wear and possible damage.The opposite end of the blade assembly 12, that is the left end from theoperators point of view, functions largely to discharge loose materialwhich has traveled across the front of the assembly.

To reduce wear and the risk of damage at the cutting end of the bladeassembly 12, retractable end bits 48R and 48L are provided at the rightand left ends respectively of the blade assembly 12. Referring again toFIGS. l, 2 and 3 in combination, end bit 48R includes an upright flatrectangular blade 49R extending adjacent belt 34. Blade 49R is pivotableabout the rotary axis of idler drum 33 from a position at which theblade outwardly utwardly from vthe end of assembly l2 to effectivelyform an extension'of the earth intercepting surface 38 thereof to aretracted position at which the blade is swung around behind theadjacent end of the conveyor belt 34 as will hereinafter be described inmore detail.

To support blade 49R in this manner, a rotatable vertical shaft 51R isdisposed along the axis of drum 33 and extends a small distance aboveand below the drum and frame 31. Upper and lower pivot arms 52R and 53Rextend radially from the ends of shaft SIR above and below the frame.Upper and lower triangular brackets 54R and 56R respectively attachblade 49R to arms 52R and 53R respectively. lf desired, blade 49R, pivotarms 52R and 53R, and brackets 54R and 56R may readily be formed as asingle integral element.

The left end bit 48L is of essentially similar construction and thusincludes an upright blade 49L attached to a vertical shaft SIL whichextends along the axis of drive drum 32, upper and lower pivot arms 52Land 53L, respectively, and upper and lower brackets 54L and 56L,respectively, which attach the blade member to the upper and lower pivotarms.

When either of the end bits 48 is in the active position at which theassociated blade 49 forms an extension of the earth intercepting surface38, the direction of movement of the conveyor belt 34 is such as toprevent jamming of rocks or the like between the conveyor and thatparticular blade. However, this is not true of the blade 49 at theopposite or discharge end of the assembly 12 wherein the conveyormovement tends to pull such objects into the gap between the belt andblade 49. Accordingly, the present invention provides for retraction ofthe blade member 49 at the discharging end by swinging such bladepartially around the adjacent end of conveyor belt 34. At the retractedposition the blade 49 is out of the principal path of travel ofmaterials discharging around the conveyor end and is obliquely inclinedrelative to such path, the left end bit 48L being in this retractedposition in FIGS. l, 2 and 3.

As the operator may wish to use flrst one end of the blade assembly l2as the cutting end and then use the other end for such purpose withoutdismounting from his station 14 to make adjustments, it is advantageousto provide powered means for Shifting the end bits so that either can beselectively moved to the active position while the other issimultaneously retracted. One means for this purpose, depicted in FIGS.l to 3, consists of a triangular plate 57 pivotable on a vertical axle58 mounted at the center of the top surface of frame 31. A hydraulicjack 59 has one end pivotably coupled to the left angled member 26L andthe other end pivotably coupled to one point of triangular plate 58whereby extension of the jack turns plate 58 in one direction andcontraction of the jack turns the plate in the opposite direction. Aright link 61R is pivotably connected between end bit pivot arm 52R andanother point of triangle 58 while a left link 61L is pivotablyconnected to the third point of plate 58 and upper pivot arm 52L of theleft end bit. Plate S8 and links 61 are proportioned, relative to thestroke of jack 59, whereby retraction of the jack forces the right endbit 48R into the active position while pivoting the left end bit 48Linto the inactive position while extension of the jack shifts end bit48L into the active position while retractingend bit 48R.

It will be appreciated that other structure may be used to provide foralternate movement of an end bit between an active position and aninactive position. For example,-the end bits need not necessarily pivotabout vertical axes as in the above described embodiment and a lesscomplex and costly system is possible where shifting of the end bit andsecuring the end bits in either position are performed manually. FIGS. 4and S in conjunction illustrate a second embodiment in the inventionwherein both of these modifications are present.

In the embodiments of FIGS. 4 and 5, the blade assembly 12' may beessentially similar to that of the previously described embodimentinsofar as the frame 31 drums 32' and 33', motor 39', belt 34' andcutting edge 44 are concerned and accordingly such elements will not beredescribed in detail. To support the end bits 48R' and `48L' in thisembodiment a fixed shaft 62 extends along the top surface of frame 3l inparallel relationship therewith and in parallel relationship with theforward surface 38' of the conveyor, the shaft being secured to frame31' by suitable brackets 63.

The end portions 64R and 64L of shaft 62 which extend beyond the ends ofbelt 34 at the right and left ends respectively are of reduced diameter.Each endbit 48R and 481.' consists of a rectangular blade 66 hav ing asleeve 67 formed along the upper edge thereof for disposition on theassociated end portion 64R or 64L of shaft 62. A washer 68 is disposedon each shaft end 64 between sleeve 67 and the larger diameter portionof the shaft and a threaded nut 69 or other suitable fastening meansretains the sleeve on the shaft end portion. Thus each blade 66 may beswung upward to a substantially horizontal inactive position as depictedat 4BR in FIG. 4 or may be swung downward to an active position asdepicted at 48L to form an extension of the earth intercepting surface38' of the conveyor 34.y

To provide for securing each blade 66 in either of the above describedpositions, an angled bracket 71 is secured to the back surface of theblade at the comer which is adjacent conveyor belt 34' and remote fromsleeve 66, the bracket having a bore 72 therethrough.

Each bracket 63 has an upwardly and outwardly extending arm 73 with abore 74 positioned to be in alignment with bore 72 when the plate 66 isswung upward to the inactive position. Thus a bolt 76 or other suitablefastener may be inserted through bores 72 and 74 to secure the end bitin the inactive position. To secure the end bit in the lowered or activeposition, angled brackets 77 are secured to lower portion of frame 31 ateach end thereof and have bores 74 positioned to receive the bolts 76when the associated end bit is in the lowered or active position. As inthe previously described embodiment, the particular end bit 48 adjacentthe end of the assembly 12' at which conveyor belt 34 is travelingforwardly is normally fixed in the active position while the end bit atthe opposite end of the assembly wherein the material is beingdischarged is fixed at the inactive or raised position.

While the invention has been described with respect to certain exemplaryembodiments, it will be apparent that many other modifications arepossible and it is not intended to limit the invention except as definedin the following claims.

What is claimed is:

l. A blade assembly for a motor grader comprising:

an endless belt conveyor,

a means having meahs for attachment to said motor grader and havingmeans for supporting said belt conveyor in a substantially transverserelationship thereto to provide an earth intercepting surface as saidmotor grader travels forward and having reversible drive means fordriving said conveyor belt to carry intercepted earth from a selectedend of -said conveyor belt to the opposite end thereof,

a first end bit blade disposed adjacent said one end of said conveyorbelt,

means for attaching said first end bit blade to said frame and havingmeans providing for shifting of said blade between an active position atwhich said blade forms an extension of said earth intercepting surfaceat said one end of said conveyor belt and an inactive positionl at whichsaid blade is retracted away from said active position, i

a second end bit blade disposed at said opposite end of said conveyorbelt and means for attaching said second end bit blade to said frame andhaving means providing for shifting of said second end bit blade betweenan active position at which said second blade forms an extension of saidearth intercepting surface at said opposite end of said conveyor beltand an inactive position at which said second blade is retracted awayfrom said inactive position thereof.

2. A blade assembly for a motor grader comprising:

an endless belt conveyor,

a frame having means for attachment to said motor grader and havingmeans for supporting said belt conveyor in a substantially transverserelationship thereto to provide an earth intercepting surface as saidmotor grader travels forward and having means for driving said conveyorbelt to carry intercepted earth from one end of said conveyor belt tothe opposite end thereof,

a first end bit blade disposed adjacent said one end of said conveyorbelt,

means for attaching said first end bit blade to said frame and havingmeans providing for shifting of said blade between an active position atwhich said blade forms an extension of said earth intercepting surfaceat said one end of said conveyor belt and an inactive position at whichsaid blade is retracted away from said active position,

a second end bit blade disposed at said opposite end of said conveyorbelt and means for attaching said second end bit blade to said frame andhaving means providing for shifting of said second end bit blade betweenan active position at which said second blade forms an extension of saidearth intercepting surface at said opposite end of said conveyor beltand an inactive position at which said second blade is retracted awayfrom said inactive position thereof, and

linkage means connected with each of said end bit blades for shiftingone of said blades to said inactive position thereof while shifting theother of said blades to said active position.

3. A blade assembly as defined in claim 2 wherein said means forattaching said first end bit blade to said frame comprises a first pivotarm rigidly connected to said first blade and being pivotally coupled tosaid frame for pivoting movement about a substantially vertical axisthrough said one end of said conveyor belt and wherein said means forattaching said second end bit blade to said frame comprises a secondpivot arm rigidly attached to said second blade and being pivotallycoupled to `said frame for pivoting movement about a substantiallyvertical axis through said opposite end of said conveyor belt, saidlinkage means comprising a pivotable element mounted on said framebetween said ends thereof, first and second links each connected betweena separate one of said pivot arms and said pivotable element, andpowered means for selectively pivoting said pivotable element.

4. A blade assembly for a motor grader comprising:

an endless belt conveyor,

a frame having means for attachment to said motor grader and havingmeans for supporting said belt conveyor in a substantially transverserelationship thereto to provide an earth intercepting surface as saidmotor grader travels forward and having means for driving said conveyorbelt to carry intercepted earth from one end of said conveyor belt tothe oppositeend thereof,

a first end bit blade disposed adjacent said one end of said conveyorbelt,

means for attaching said first end bit blade to said frame and havingmeans providing for shifting of said blade between an active position atwhichsaid blade forms an extension of said earth intercepting surface atsaid one end of said conveyor belt and an inactive position at whichsaid blade is retracted away from said active position, wherein saidmeans for attaching said first end bit blade to said frame comprises ashaft extending from said frame at said one end of said conveyor belt,means pivotably coupling said first end bit blade to said shaft, andmanually disengageable means for fixing said first end bit blade againstmotion relative to said shaft at said active position thereof and atsaid inactive position thereof.

5. A blade assembly as'defined in claim 4 wherein

1. A blade assembly for a motor grader comprising: an endless beltconveyor, a means having meahs for attachment to said motor grader andhaving means for supporting said belt conveyor in a substantiallytransverse relationship thereto to provide an earth intercepting surfaceas said motor grader travels forward and having reversible drive meansfor driving said conveyor belt to carry intercepted earth from aselected end of said conveyor belt to the opposite end thereof, a firstend bit blade disposed adjacent said one end of said conveyor belt,means for attaching said first end bit blade to said frame and havingmeans providing for shifting of said blade between an active position atwhich said blade forms an extension of said earth intercepting surfaceat said one end of said conveyor belt and an inactive position at whichsaid blade is retracted away from said active position, a second end bitblade disposed at said opposite end of said conveyor belt and means forattaching said second end bit blade to said frame and having meansproviding for shifting of said second end bit blade between an activeposition at which said second blade forms an extension of said earthintercepting surface at said opposite end of said conveyor belt and aninactive position at which said second blade is retracted away from saidinactive position thereof.
 2. A blade assembly for a motor gradercomprising: an endless belt conveyor, a frame having means forattachment to said motor grader and having means for supporting saidbelt conveyor in a substantiAlly transverse relationship thereto toprovide an earth intercepting surface as said motor grader travelsforward and having means for driving said conveyor belt to carryintercepted earth from one end of said conveyor belt to the opposite endthereof, a first end bit blade disposed adjacent said one end of saidconveyor belt, means for attaching said first end bit blade to saidframe and having means providing for shifting of said blade between anactive position at which said blade forms an extension of said earthintercepting surface at said one end of said conveyor belt and aninactive position at which said blade is retracted away from said activeposition, a second end bit blade disposed at said opposite end of saidconveyor belt and means for attaching said second end bit blade to saidframe and having means providing for shifting of said second end bitblade between an active position at which said second blade forms anextension of said earth intercepting surface at said opposite end ofsaid conveyor belt and an inactive position at which said second bladeis retracted away from said inactive position thereof, and linkage meansconnected with each of said end bit blades for shifting one of saidblades to said inactive position thereof while shifting the other ofsaid blades to said active position.
 3. A blade assembly as defined inclaim 2 wherein said means for attaching said first end bit blade tosaid frame comprises a first pivot arm rigidly connected to said firstblade and being pivotally coupled to said frame for pivoting movementabout a substantially vertical axis through said one end of saidconveyor belt and wherein said means for attaching said second end bitblade to said frame comprises a second pivot arm rigidly attached tosaid second blade and being pivotally coupled to said frame for pivotingmovement about a substantially vertical axis through said opposite endof said conveyor belt, said linkage means comprising a pivotable elementmounted on said frame between said ends thereof, first and second linkseach connected between a separate one of said pivot arms and saidpivotable element, and powered means for selectively pivoting saidpivotable element.
 4. A blade assembly for a motor grader comprising: anendless belt conveyor, a frame having means for attachment to said motorgrader and having means for supporting said belt conveyor in asubstantially transverse relationship thereto to provide an earthintercepting surface as said motor grader travels forward and havingmeans for driving said conveyor belt to carry intercepted earth from oneend of said conveyor belt to the opposite end thereof, a first end bitblade disposed adjacent said one end of said conveyor belt, means forattaching said first end bit blade to said frame and having meansproviding for shifting of said blade between an active position at whichsaid blade forms an extension of said earth intercepting surface at saidone end of said conveyor belt and an inactive position at which saidblade is retracted away from said active position, wherein said meansfor attaching said first end bit blade to said frame comprises a shaftextending from said frame at said one end of said conveyor belt, meanspivotably coupling said first end bit blade to said shaft, and manuallydisengageable means for fixing said first end bit blade against motionrelative to said shaft at said active position thereof and at saidinactive position thereof.
 5. A blade assembly as defined in claim 4wherein said shaft extends from said frame at said one end of saidconveyor belt above said upright earth intercepting surface and inparallel relationship to said surface.